I. Field of the Invention
The present invention relates to the conversion of digital matricies, especially matricies which correspond to digitized images, and particularly to the high speed machine reading of indicia such as, by way of example only, characters printed within fields delimited by guides which are visible to optical character recognition apparatus. More specifically, this invention is directed to apparatus which enables optical character recognition equipment to recognize and encode indicia, small artifacts such as dots for example, and to take a predetermined conversion action commensurate with the recognized indicia. Accordingly, the general objects of the present invention are to provide novel and improved methods and apparatus of such character.
II. Brief Description of the Prior Art
While not limited thereto in its utility, the present invention is particularly well suited for use with commercially available optical character recognition (OCR) apparatus having the ability to "read" hand-printed characters in real time, i.e., at high speed, and with very low rejection rates. An example of such optical character recognition apparatus is disclosed in U.S. Pat. No. 4,628,532. In order to enable the machine reading of data imprinted on a document by means of a visible medium, the location and size of the characters comprising such data must meet certain criteria. Thus, each character must be positioned substantially entirely within a locatable "field" and there must be a relatively high degree of contrast between the character and background. Where the data is to be entered by hand, such fields are customarily defined by printed data entry guides. Since optical character recognition apparatus operates by detecting the variations in contrast between the characters to be recognized and the background, it has been common practice to employ "drop-out" colors, i.e., colors which are invisible to the OCR equipment, to define the fields. In theory, employment of such "drop-out boxes" ensures proper sizing and positioning of hand printed data entries. The use of "drop-out" colors requires the capability of printing the documents upon which the data is to be entered in at least two colors and this significantly increases the cost of such documents. Further, the need to employ "drop-out" colors greatly increases the difficulty of changing forms upon which data is to be entered by hand.
Continuing the above discussion, and employing machine readable tax forms as an example, each year the text and format of many standard tax forms and the forms employed by accountants to solicit taxpayer information must be changed. In addition, it is often desirable that sets of such forms be assembled on the basis of individual requirements. The preparation of such preprinted forms employing "drop-out boxes" has been a relatively expensive task and the collation of individual forms to produce sets customized for particular individuals has been a time-consuming task.
The recent commercial availability of high-speed Laser printers provides the ability to create complete forms on blank paper in a single pass. While these forms can include graphics, including guides for data entry, currently available Laser printers cannot produce such guides in "drop-out" colors.
It is also to be noted that there has been a long-standing need for a means of converting input pixel patterns, commensurate with a scanned image, to other patterns in real time and with modest cost. While pixel pattern enhancement of satellite acquired images is known, the available equipment and techniques for such pattern enhancement are very expensive and complex and process data at a very slow rate.